Which of these is not real?

Distilled water is expensive and is best used in small amounts such as for watering cuttings and seedlings. European bottled water has the guaranteed analysis printed on the label, but in the USA, no specific analysis is available on the label. The dissolved solids in this bottled water are measured in milligrams per liter (mg/L).

pre-filter to RO filters to extend the life of RO filters.

Other processes such as ultrafiltration and ultraviolet oxidation, also remove salts and pollutants from water. Check www.wikipedia.org for more information.

Reverse Osmosis (RO) Water

Reverse-osmosis machines are used to separate dissolved solids from water. These machines move the solvent (water) through the semipermeable membrane. The process is accomplished by applying pressure to the “tainted” water to force only “pure” water through the membrane. The water is not totally (EC of zero), but most of the dissolved solids are removed. The efficiency of reverse osmosis depends on the type of membrane, the pressure differential on both sides of the membrane, and the chemical composition of the dissolved solids in the tainted water. Unfortunately, common tap water often contains high levels of sodium (Na), calcium (Ca), alkaline salts, sulfur (S), chlorine (Cl) and other minerals. The pH could also be out of the acceptable 6.5 to 7 range.

Sulfur is easily smelled and tasted in water. Saline water is a little more diffi- cult to detect. Water in coastal areas is generally full of salt that washes inland from the ocean or sea. Dry regions that have less than 50.8 cm annual rainfall also suffer from alkaline soil and water that is often loaded with alkaline salts. This reverse osmosis machine transforms water with a high ppm or EC into “clean” water

Jorge Cervantes is author of the Cannabis Encyclopedia (596 pages, 2,000+ color images, large A4 format) and Marijuana Horticulture (AKA the Bible). Booth books are available at all amazon retailers worldwide. The Cannabis Encyclopedia has an excellent chapter on water. Contact Jorge at www.marijuanagrowing.com.